Impact of Gastric Banding Versus Metformin on β-Cell Function in Adults With Impaired Glucose Tolerance or Mild Type 2 Diabetes

Diabetes Care. 2018 Dec;41(12):2544-2551. doi: 10.2337/dc18-1662. Epub 2018 Oct 3.

Abstract

Objective: Type 2 diabetes (T2D) results from progressive loss of β-cell function. The BetaFat study compared gastric banding and metformin for their impact on β-cell function in adults with moderate obesity and impaired glucose tolerance (IGT) or recently diagnosed, mild T2D.

Research design and methods: Eighty-eight people aged 21-65 years, BMI 30-40 kg/m2, with IGT or diabetes known for <1 year, were randomized to gastric banding or metformin for 2 years. Hyperglycemic clamps (11.1 mmol/L) followed by arginine injection at maximally potentiating glycemia (>25 mmol/L) were performed at baseline, 12 months, and 24 months to measure steady-state C-peptide (SSCP) and acute C-peptide response to arginine at maximum glycemic potentiation (ACPRmax) and insulin sensitivity (M/I).

Results: At 24 months, the band group lost 10.7 kg; the metformin group lost 1.7 kg (P < 0.01). Insulin sensitivity increased 45% in the band group and 25% in the metformin group (P = 0.30 between groups). SSCP adjusted for insulin sensitivity fell slightly but not significantly in each group (P = 0.34 between groups). ACPRmax adjusted for insulin sensitivity fell significantly in the metformin group (P = 0.002) but not in the band group (P = 0.25 between groups). HbA1c fell at 12 and 24 months in the band group (P < 0.004) but only at 12 months (P < 0.01) in the metformin group (P > 0.14 between groups). Normoglycemia was present in 22% and 15% of band and metformin groups, respectively, at 24 months (P = 0.66 between groups).

Conclusions: Gastric banding and metformin had similar effects to preserve β-cell function and stabilize or improve glycemia over a 2-year period in moderately obese adults with IGT or recently diagnosed, mild T2D.

Trial registration: ClinicalTrials.gov NCT01763346.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Aged
  • Blood Glucose / metabolism
  • Diabetes Mellitus, Type 2* / complications
  • Diabetes Mellitus, Type 2* / drug therapy
  • Diabetes Mellitus, Type 2* / physiopathology
  • Diabetes Mellitus, Type 2* / surgery
  • Female
  • Gastroplasty* / adverse effects
  • Gastroplasty* / methods
  • Glucose Intolerance* / complications
  • Glucose Intolerance* / drug therapy
  • Glucose Intolerance* / physiopathology
  • Glucose Intolerance* / surgery
  • Glucose Tolerance Test
  • Humans
  • Insulin Resistance / physiology
  • Insulin-Secreting Cells / drug effects
  • Insulin-Secreting Cells / physiology*
  • Male
  • Metformin / therapeutic use*
  • Middle Aged
  • Obesity / complications
  • Obesity / drug therapy
  • Obesity / physiopathology
  • Obesity / surgery
  • Severity of Illness Index
  • Young Adult

Substances

  • Blood Glucose
  • Metformin

Associated data

  • ClinicalTrials.gov/NCT01763346